An electromagnet is a temporary magnet made by coiling wire around an iron core which becomes a magnet when an electric current flows through the wire.
How could the strength of an electromagnet be increased?
A) Use fewer coils of wire around the nail.
B) Use more coils of wire around the nail.
C) Use a battery with less voltage.
D) Use a smaller nail.

USE MORE COILS OF WIRE AROUND THE NAIL

Explanation:

To increase the strength of an electromagnet, the following strategy is adopted in order to have better efficiency.

The best method which suits for increasing the strength of electromagnet is to increase the number of turns around the nail.

If we increase the number of turns up to a specific value the magnetizing property of magnet is enhanced. So that to increase the strength , add more number of turns to the existing turns of coil.

i was thinking more like reflects green light, just not sure

c. newton's third law of motion